since we have 8 bits spare, so there's no chance of confusing it
with an ICAO address, and we can safely use the filter table to match
future messages without also matching equivalent ICAO addresses.
Switch signalLevel back to a power measurement, don't put SNR in there.
But make it a 0.0 - 1.0 double so we're not scaling everywhere.
Adjust for the amplitude offset when calculating power.
Adapt everything else to the new scheme.
Ok - this is likely to upset some people. Up until now, the vast
majority of the code has been in just one file - dump1090.c. This file
has grown so that it was approaching of 5000 lines long, and it was
becoming unmanagable. So I've split the file into several modules,
hopefully along fairly logical boundaries. The files are :
1) dump1090.c : Basically just the main() entry function, the help
function, the RTL dongle hardware interface, and a few orphan functions
that don't really fit anywhere else.
2) mode_s.c : This contains all the mode S / ADSB decoding functions.
3) mode_ac.c : This contains all the mode A & C decoding functions
4) interactive.c : This contains all the functions to maintain an
internal list of aircraft seen over the last period, and functions to
print them out to the local console.
5) net_io.c : This contains all the network input/output functions
allowing data to be passed in/out to/from other receivers, in formats
such as SBS-1/3, Beast, AVR and JavaScript.
Hopefully this should provide an easier way forward if/when more
functions are added.